 BetterPhoto Member |
black line across bottom of pic jacqueline
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- Gregory LaGrange Contact Gregory LaGrange Gregory LaGrange's Gallery |
Shutter speed was too high. Look in the manual to see what is called the sync speed. Don't set your shutter speed above that when you're using a flash.
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Alan N. Marcus |
Hi Jacqueline, The shutter of your camera acts like a trap door, it springs open allowing the imaging chip (film) to be bathed with light focused by the lens. There are two types shutter mechanisms in common usage. 1. A shutter located up-front, actually within the lens itself. This design is know as a between-the-lens shutter. It opens, first as a tiny hole or opening and then the hole size expands until the shutter is completely open. Then it closes revering this action. The other type, the type you have is located at the back of the camera just in front of the chip (or film). This type is called a focal plane shutter because the lens is focused to produce an image on the flat surface (plane) of the chip (or film). This location is called the focal plane. This shutter contains a slit that moves across the chip (film) uncovering and then capping, first the top part and than sweeping down until all of the chip’s (film’s) surfaces has seen the light from the lens. Now it takes time for the shutter to open and close, even when the shutter is set to a fast speed. When the flash goes off, the duration of the electronic flash is very short. In fact it is so very quick that if the camera only sees things by the light of the flash, all subject motion is arrested. That the way, we can shoot pictures of hummingbird wings and bullets and other fast objects; Stated another way, the flash is a pulse of light that is very very quick. Now the flash is so quick that if it fires off while the shutter is still in the process of opening or closing, the shutter will partially block the chip (film). When this happens you get partial image. In your case the bottom of the chip is still covered by the fast moving shutter and you are seeing the shadow of the shutter. Read your camera manual. You need to find out what is the fastest shutter speed that will not synchronize with your flash (called X synchronization). Likely you must use a maximum of 1/250 sec or perhaps 1/125 second when using the flash. Likely the optimal shutter speed will have the symbol of a lightning bolt . Alan Marcus
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